1. Field of the Invention
The present invention pertains to a silver alloy foil for use in an interconnector of a Si or Ga-As solar cell employed in satellites or the like, and in particular to a foil which is less susceptible to softening even when the solar cell is exposed to temperature cycling.
2. Prior Art
As disclosed in Japanese Patent Application 18-Month Publication No. 62-101441, the same applicant developed a foil for an interconnector of a solar cell which was made of silver alloy containing 1O to 1OOO ppm by weight (hereinafter referred to as "ppm") of calcium, balance silver and unavoidable impurities. In this silver alloy foil, the characteristics do not change with the passage of time as long as the circumstances remain unchanged.
However, when the above silver alloy foil is exposed to severe temperature cycling which may occur in outer space, the characteristics, in particular the hardness, gradually decrease as time passes, and hence it is difficult to maintain the characteristics so as not to deteriorate over a prolonged period of time.